Idiopathic pulmonary fibrosis with emphysema: Evidence of synergy among emphysema and idiopathic pulmonary fibrosis in smokers

Abstract

BACKGROUND: Emphysema and fibrosis, typically the idiopathic pulmonary fibrosis (IPF) form of usual interstitial pneumonia (UIP), can co-exist as combined pulmonary fibrosis emphysema (CPFE). It is unknown whether there is a pathobiologic basis for CPFE beyond the coexistence of fibrosis and emphysema. The aim of this study was to ascertain radiologic differences in severity of fibrosis and emphysema in smokers with IPF versus other forms of UIP. METHODS: Computed tomography thorax images were prospectively rescored in retrospectively identified smokers (minimum 5-pack-year history) with radiologic UIP (any etiology). Radiologic severity (emphysema/fibrosis/reticulation) was scored in consensus by two radiologists, blinded to clinical details, across 5 lung regional levels, and then correlated with clinical data. RESULTS: For the whole cohort (IPF, n = 102; non-IPF UIP [mainly rheumatoid arthritis/asbestosis/scleroderma], n = 30), IPF and non-IPF UIP smokers were similar regarding pack-year, age, gender, and lung function (P > .1). IPF smokers had greater whole lung fibrosis and reticulation scores (P.1). There were significantly greater regional reticulation severity (P = .009), cumulative emphysema severity (P = .04), and cumulative reticulation severity (P